Color separation negatives for color printing reproduction of a positive color transparency are presently produced through the utilization of half-tone screens and continuous tone negative transparency masks. The maximum density range of most original transparencies is greater than can be reproduced with paper and inks. Therefore, the density range is reduced by making a continuous tone negative of the transparency on film and is called a mask. When placed in registry, the density range of the image projected is reduced to the range most papers and inks can print. Although this process is well-known and established, superlative results may not always be obtained without "flashing" or "bumping" and the use of a continuous tone negative transparency mask requires special skills which are learned, for the most part, through extensive schooling and at a great expense. Further, although large newspapers have sufficient quantity of color printing to warrant the salary of an experienced person for color separation work, smaller newspapers, for example, do not have a large enough color printing load to warrant the salary of such a specialized person.
In addition, the use of a continuous tone negative transparency mask when preparing color separation negatives inherently involves at least some misalignment of the mask and the color positive transparency to be reproduced, even though locating pins may be utilized, and the sharpness of edges between closely adjacent high and low density areas of the positive color transparency is reduced, at least to some degree.
Accordingly, a need exists for a method of preparing color separation negatives for color printing which does not require the use of a continuous tone negative transparency mask.